In various filtration and diffusion devices, including those in the above-identified U.S. patent applications, these devices generally have a sealing ring which is in the form of an O-ring arranged between an end wall and a cup-shaped lid member therefor. It has been found in practice, however, that it is extremely difficult to provide exactly the required degree of tightening pressure in these devices when using such O-rings. This is particularly true when the lid is to be welded to the housing. Therefore, in order to obtain the desired degree of tightening pressure the lid must be placed in a special position regarding the housing within extremely narrow limits.
One type of sealing ring which is disclosed in the prior art is shown in French Patent No. 2,088,735. However, this type of sealing ring cannot provide the improved deformation in response to various deformation forces over a wide range thereof. Another type of sealing ring is disclosed in Swedish Patent No. 392,640. In this case, as with the aforementioned French patent, it includes an inwardly directed concave surface. Furthermore, the sealing ring is not compressed between a pair of parallel surfaces, but is compressed by a sloping surface, which thus provides characteristics of deformation in response to deformation forces which are limited to deformation by bending in only a small portion of the sealing ring, with the shape of the sealing ring maintained relatively constant by the shape of the housing within which it is maintained. It is, therefore, an object of the present invention to solve these prior difficulties which have become rather common for a number of different technical fields. Thus, it will be understood that particular advantage can be achieved by using the seals of this invention in connection with these types of filtration and/or diffusion devices, although one of ordinary skill in this art will recognize that these seals can be used advantageously for other purposes.